1. Field of the Invention
The invention relates to a cover device for a fan and more particularly to a cover device for a wall fan to protect the wall fan from rain and bad weather.
2. Description of the Related Art
A conventional wall fan is shown in FIG. 1. The wall fan has a casing A having a front opening (not shown) and a rear opening provided with grilles Al. A fan unit is disposed inside the casing A and includes a motor B to control the movement of fan blades C. The rear opening of the casing A serves as an air passage during the operation of the fan. The wall fan is mounted in an opening in a wall of an enclosed space for ventilation. During cold and/or rainy weather, the wall fan is seldom used and thus, the casing A becomes an unnecessary passage in the wall through which undesirables, such as rats, insects, and cold air, can enter the enclosed space. Moreover, over a long period of time, exposure of the wall fan to rain water and bad weather reduces the service life of the wall fan.